This research will exploit a unique data source (German village genealogies) in order to explore preindustrial population dynamics and the transition to modern patterns of demographic behavior in four German villages. The genealogies are usually valuabel for several reasons: They are already in the form of reconstituted family histories, sparing countless hours of preparatory work. 2) Unlike other genealogies, they refer to entire village populations and not selected families or social strata. 3) They permit analyses not only of the preindustrial past but also the critical period of the fertility transition, rarely covered by other studies using reconstitution data. 4) Occupational data are included permitting analysis of socioeconomic differentials. 5) The genealogies represent a wide variety of geographical and demographic settings. The analysis will give special attention to temporal change. One focus will be the interrelationship of child mortality and fertility. Because the data are micro-level, they permit direct estimation of the "Physiological" and "replacement" effects of child mortality on fertility. Particularly valuable is the opportunity for exploring changes in this relationship during the demographic transition. The influence of birth interval length, family size, and parity on mortality risks of offspring will also be examined. Another focus will be natural fertility and family limitation with special attention to evidence of control prior to the fertility decline and the transformation from pre-industrial to modern childbearing patterns. The data permit an individual level analysis not possible with the aggregate data used in previous studies of the demographic transition. Other foci include illegitimacy, bridal pregnancy and nuptiality. The data also permit exploring generational links in illegitimacy and its consequences for the mother's marriage prospects and the life chances of the children. Changes in illegitimacy and nuptiality can be related to the establishment and repeal of restrictive marriage legislation. Occupational differentials in illegitimacy and bridal pregnancy will shed light on secular changes in sexual behavior.